The 25th Infantry Division (Polish: 25 Dywizja Piechoty) was a unit of the Polish Army in the interbellum period, created in 1921 with headquarters in Kalisz. It consisted of the following regiments:
During the Polish September Campaign the Division, under General Franciszek Alter, was part of the Poznaà  Army. It took part in the border battle, defending Krotoszyn on 1 September 1939. However, parts of the 56th Infantry Regiment were defeated near Rawicz.
For the next days, the Division was in retreat, together with the whole Army. On 8 September it was positioned near Koà Âo, then it took part in the Battle of the Bzura, attacking the Germans at Ozorków and à ÂÃÂczyca. In the evening of 9 September the division managed to recapture à ÂÃÂczyca, but a few days later it was ordered to retreat. On 17 September the unit forced its way into the Kampinos Wilderness, where it soon afterwards engaged in bloody skirmishes. After 20 September the remnants of the Division reached Warsaw, taking part in the defence of the city.